Consumer Reports conducted a survey of 1,000 Americans to see how many engaged in everyday prevention behaviors (ConsumerReports.org, 2009). As shown in Table 16.2, the respondents did rather well in a number of categories (91% read the warnings that come with a prescription drug, and 87% report not drinking beer while using a power tool or mower) but neglected some obvious preventive steps (58% never wear a bike helmet, 24% report being in a car without using a seat belt, and 27% do not use sunscreen when outdoors for an extended period). We do worry about those 13% who are drinking beer while using power tools or mowing the lawn, but the point is that many of our choices contribute to the prevention of accidents and disease.
Table 16.2
Americans’ Safety Practices
Behavior | Yes | No |
Use cotton swabs to clean ears | 73% | 26% |
Let your kids play on a trampoline | 43% | 56% |
Eat raw dough when making cookies | 39% | 61% |
Use the top step of a ladder | 31% | 69% |
Fail to use the car’s seat belt | 24% | 75% |
Drink beer while using a power tool or mower | 13% | 87% |
Have a rubber mat in the shower | 39% | 61% |
Have a carbon-monoxide detector in home | 51% | 48% |
Eat burgers only well done | 67% | 32% |
Change batteries in the smoke alarm annually | 79% | 21% |
Clean lint trap in the dryer after each use | 81% | 18% |
Read warnings on prescription medicines | 91% | 9% |
Wear a bike helmet | 42% | 58% |
Wear sunscreen when outside for an extended time | 73% | 27% |
Source: Adapted from “Risky Business,” by ConsumerReports.org, 2009, retrieved from http://www.consumerreports.org/cro/magazine-archive/march-2009/money/risk-taking/overview/risk-taking-ov.htm Behaviors that contribute to our major causes of death include smoking, poor nutrition, alcohol use, lack of exercise, and loneliness (see Figure 16.13), which are discussed in more detail in the following sections.
Tobacco Use
Cigarette smoking is considered to be the leading preventable cause of death in the United States, with a direct responsibility in one of five deaths each year (CDC, 2014). On average, smokers die 13–14 years earlier than nonsmokers. Tobacco use can lead to additional health problems. Nicotine is a well- established gateway drug, capable of producing epigenetic changes that increase the likelihood of addiction to cocaine (Li et al., 2014). Tobacco’s effects are not restricted to its users either. In the United States, exposure to secondhand smoke leads to 3,400 lung cancer deaths, 46,000 heart disease deaths, 430 cases of sudden infant death syndrome (SIDS), 24,500 low-birth-weight babies, 71,900 preterm deliveries, and 200,000 episodes of childhood asthma each year (WHO, 2008).
Cigarette smokers in the United States dropped from 21% of adults in 2005 to just 15% in 2015 (Jamal et al., 2016) (see Figure 16.14). Worldwide, however, rates of smoking are higher than those found in the United States and other developed countries. According to the WHO (2008), two thirds of current smokers live in developing countries, with 30% of smokers residing in China and 10% in India. Gender, race, ethnicity, education, mental health, and income are strong determinants of the likelihood of smoking. In the United States, men are more likely to smoke than women (16.7%, as opposed to 13.6%). American Indians or Alaska Natives reported the highest incidence of smoking (21.9%), followed by non-Hispanic multirace individuals (20.2%), non-Hispanic Whites (16.6%), non-Hispanic Blacks (16.7%), Hispanics (10.1%), and Asians (7.0 %). Lesbian/gay/bisexual individuals were more likely to smoke cigarettes (20.6%) than heterosexual individuals (14.9%). Smoking drops with increasing education, from 34.1% of individuals with a general equivalency diploma (GED) certificate to 3.6% of adults with a graduate degree. Poverty plays a strong role in smoking; 26.1% of adults living below the poverty line compared to 13.9% living at or above the poverty line report smoking.
You might be wondering how trends regarding e-cigarettes (i.e., vaping) might influence these numbers. In 2015, 3.5% of U.S. adults used e-cigarettes, and 58% of these are also current cigarette smokers (CDC, 2016). Among e-cigarette users aged 18–45, 40% have never used regular cigarettes. It is unclear how much of the overall decline in cigarette use is related to e-cigarette use. E-cigarettes often contain levels of nicotine capable of producing addiction, but their overall, long-term health implications remain relatively unknown (Harrell, Simmons, Correa, Padhya, & Brandon, 2014). Secondhand exposure to the vapor from e-cigarettes presents less risk than to conventional cigarette smoke, but it nevertheless has the potential to produce adverse health outcomes (Hess, Lachireddy, & Capon, 2016).
Given the carnage produced by tobacco, why do people start smoking and then continue? An understanding of the initiation of tobacco use requires combining the perspectives discussed in this textbook—development, biological psychology, learning, cognitive, clinical, and social/personality psychology.
Most tobacco users begin smoking in childhood or early adolescence, long before decision-making abilities are mature. Because of the addictive nature of nicotine, about half of those who experiment with tobacco continue to use it. In addition to its action on synapses where the neurotransmitter acetylcholine is released, as discussed in Chapter 6, nicotine has the ability to stimulate the dopamine reward circuits of the brain and to produce a particularly unpleasant set of withdrawal symptoms. As discussed in Chapter 11, adolescence is also a time when people try out new roles and learn important skills for getting along with peers, frequently making them susceptible to peer pressure. Teens often overestimate how many other people are using tobacco, so they might begin using it to avoid looking “different” (IOM, 1994). Finally, most smokers have friends and parents who also smoke, suggesting a role for social learning (Biglan, Duncan, Ary, & Smolkowski, 1995).
A troubling aspect of the initiation of smoking is the prevalence of tobacco use among people with diagnosed psychological disorders (see Figure 16.15). Of the approximately 20% of American adults diagnosed with any mental disorder (see Chapter 14), 40.6% were current smokers—a much higher rate than that found in the general population (Jamal et al., 2016). Adults diagnosed with mental disorders smoke 31% of all cigarettes consumed by adults in the United States (CDC, 2013b). Tobacco use among people with schizophrenia and other severe mental illnesses is about 70% in the United States, more than three times as high as the approximately 20% of users in the general population, as reported by the CDC (Dixon et al., 2007).
In addition, the severity of smoking among these individuals, which includes such factors as how many cigarettes are smoked per day, appears to be much higher among people with psychological disorders than in the general population. In a large-scale study of more than 50,000 adults who did not live in mental institutions, individuals with serious psychological distress (a global measure of psychological disorder) were more likely to smoke currently and heavily and were less likely to quit than individuals without serious psychological distress (Sung, Prochaska, Ong, Shi, & Max, 2011). Although many smokers with psychological disorders report using cigarettes to feel better, most began smoking long before their symptoms emerged and they were diagnosed with a disorder (Sacco, Termine, & Seyal, 2005).
People do quit smoking, although many find it difficult. Again, the social nature of our species plays a role in this process. A person’s chances of successfully quitting are reduced by 67% if a spouse smokes, 25% if a sibling smokes, 36% if a friend smokes, and 34% if a coworker smokes (Schroeder, 2008). We are not advocating that a prospective quitter abandon the essential social support needed at a difficult time; rather, we are suggesting that people trying to quit physically separate themselves when friends and family light up. As noted in Chapter 8, being exposed to conditioned stimuli, such as the smell of tobacco, can initiate a variety of conditioned behaviors that might make refusing a cigarette difficult for the person trying to quit.
Smoking cessation programs also can take advantage of the self-reference effect, discussed in Chapter 12. This effect explains the superior recall for information relevant to the self by suggesting that the self serves as an important schema for organizing information. Participants experiencing interventions for smoking that were tailored to their own lives, needs, interests, and obstacles not only were more successful at quitting smoking, but also showed brain activity in parts of the prefrontal cortex that are believed to participate in thinking about the self (Chua et al., 2011).
The benefits of quitting smoking appear within minutes to hours as the body begins to repair itself. After 5 years of abstention from smoking, risk of stroke is the same for ex-smokers and nonsmokers. After 10 years of abstention, the risk of lung cancer is cut in half. If the smoker quits before the age of 30 years, life expectancy remains the same as for someone who has never smoked (Doll, Peto, Boreham, & Sutherland, 2004).
Nutrition
Nutrition plays a significant part in overall physical development, including brain development, and is believed to be responsible for many differences in psychological and health outcomes related to SES (Rosales, Reznick, & Zeisel, 2009). People need the right amount and quality of nutrients to support optimum health and brain functioning, and being either underweight or obese is associated with reduced health. Obesity increases the rates of many chronic conditions, including heart disease, stroke, diabetes, arthritis, and breast and colon cancers. As noted previously, maintaining a body mass index (BMI) below 30 (nonobese) was one of the four protective factors associated with much lower risk of disease. Returning the U.S. population to normal weight (a BMI of between 18.5 and 24.9) would produce about the same improvement in overall life expectancy as the elimination of smoking (Stewart et al., 2009).
As mentioned in Chapter 7, not only do we face problems in the form of eating disorders, such as anorexia nervosa and bulimia nervosa, but the world also has experienced an unprecedented obesity epidemic over the last 25 years (see Figure 16.16). In the United States, the percentage of obese adults rose from 12% in 1991 to 35% in 2012 (Ogden, Carroll, Kit, & Flegal, 2014). It is likely that multiple factors have contributed to this change, including our sedentary lifestyle, increases in caloric intake, changes in the types of food that we eat, changes in sleep patterns, and social factors. WHO (2006) describes low- and middle-income countries as facing a “double burden” of disease because undernutrition and obesity occur at the same time, often in the same households. A combination of inadequate nutrition prenatally and in childhood, followed by exposure to high-calorie but nutrient-poor foods, sets the stage for a lifetime of poor health, possibly because of epigenetic factors (Haemer, Huang, & Daniels, 2009).
As was the case with smoking, we can see evidence of social factors that maintain our eating habits and weight. Our recent history of eating cheap, fatty, and sugary foods interacts with poverty. Nutritionists have raised the alarm that eating healthy foods is becoming more expensive than ever. Also, we seem to use the people around us as a measure of “how we’re doing” in terms of our weight. Having an obese spouse increases your risk of obesity by 37%, and having obese friends increases your risk by 57% (Christakis & Fowler, 2007).
As observed in Chapter 7, there are no quick fixes for obesity and poor nutrition. Many of the same challenges face people who want to lose weight that we observed among people attempting to quit smoking. One advantage that would-be ex-smokers enjoy, however, is the option of complete abstinence. In contrast, we cannot abstain from eating; instead, we must choose to eat differently. Research identifying the contagious aspects of smoking and obesity might provide a hopeful note. If people in your social circle begin to eat healthier diets and maintain healthier weights, perhaps it will become easier for you to do so as well. Although losing weight can seem difficult, small changes in behavior are helpful. People using smaller plates unconsciously ate less (Wansink, 2006).
In addition to addressing concerns about obesity, current research in nutrition is focusing on the specific nutrients needed for healthy development and psychological well-being. As mentioned in Chapter 14, prevalence of bipolar disorder is much lower in countries consuming large amounts of seafood than in countries where seafood consumption is rare (Noaghiul & Hibbeln, 2003). Although much remains to be explored in this area, a further understanding of the consequences of changes in our modern diet should help us achieve a healthier lifestyle.
Alcohol
Alcohol is widely used in the United States and in many other countries around the world (see Figure 16.17). According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA, 2017), 86.4% of American adults consumed alcohol at some point in their lifetime, 70.1% consumed alcohol in the past year, and 56.0% consumed alcohol in the past month. About 27% of the adult population engaged in binge drinking (five or more alcoholic beverages on the same occasion) during the past month, and 7% reported heavy drinking (five or more alcoholic beverages on one occasion on each of five or more days in the past month); 6% of adults and 2.5% of adolescents meet criteria for alcohol use disorder. Alcohol use is the fourth-leading preventable cause of death in the United States. Globally, about one quarter of total deaths of individuals between the ages of 20 and 39 occur due to alcohol (NIAAA, 2017).
The largest threats to health from alcohol use are to the liver, which is responsible for clearing the body of toxins, but alcohol use also contributes to lower life spans because of stroke, high blood pressure, and some cancers (breast, digestive, and liver). In the United States alone, excessive alcohol consumption leads to approximately 88,000 deaths annually, at a cost of $249 billion (NIAAA, 2017). Alcohol-impaired driving accounts for 31% of all driving fatalities in the United States.
In addition, alcohol poses a risk of abuse and dependence for many people. Psychologists define alcohol abuse as repeated use despite adverse consequences and alcohol dependence as alcohol abuse accompanied by tolerance, withdrawal, and a compulsive urge to drink more (APA, 2013). As observed in Chapter 4, tolerance is defined as the need to administer greater quantities of a drug to maintain the same subjective effect, and withdrawal refers to symptoms that occur when a habitually used drug is no longer used.
As we have seen in so many other domains of human behavior, complex interactions between biological and environmental factors lead to alcohol abuse and dependence. Genes related to the body’s ability to break down alcohol in the liver are not evenly distributed across the world’s populations. Certain types of genes found primarily in Asians are correlated with lower rates of alcohol dependence (Eng, Luczak, & Wall, 2007). To illustrate the need to consider more than simply genetic predisposition, however, see the example of Native Americans, who have much higher rates of alcohol dependence than do many other ethnic groups in the United States, despite a high prevalence of the supposedly “protective” genes (Ehlers, 2007).
Many of the same factors that encourage teens to begin smoking also encourage drinking. Most people who go on to abuse alcohol are drinking heavily by late adolescence, and most cases of alcohol dependence are well established by the age of 30 years (Enoch, 2006). This timeline provides insight into when prevention programs are likely to be most effective. Peer pressure, the need to fit in or look cool, overestimates of “Everybody’s doing it,” modeling the behavior of parents and other family members, and the teen’s characteristic sense of being immune to harm from risky behavior can contribute to decisions to begin drinking. Because alcohol reduces anxiety, socially anxious teens are especially at risk for problem drinking. If teens feel more socially competent while drinking, they are likely to continue this practice because of operant conditioning, as described in Chapter 8. Reduced feelings of anxiety are rewarding, so a person is likely to repeat the behavior (alcohol consumption, in this case) associated with this reward.
Among the environmental influences on problem drinking is the age at which people take their first drink. Individuals exposed to alcohol at earlier ages show a much higher rate of alcohol dependence later in life. Again, we find that age of first drink interacts with a person’s genetic predisposition to alcohol dependence (Agrawal et al., 2009). In yet another example of the epigenetic mechanisms discussed in Chapter 3, early exposure to alcohol might affect the expression of genes related to problem drinking. A similar interaction is found between the maltreatment and neglect of a child and the genetic vulnerability to alcohol dependence. Not all children who are maltreated go on to become dependent on alcohol, although many do (Shin, Edwards, Heeren, & Amodeo, 2009; Shin, Edwards, & Heeren, 2009). The maltreated children who do not develop drinking problems are likely to be protected by combinations of genetic predisposition and the presence of peer and parental support (Enoch, 2006).
Treatment for very heavy drinkers often requires medical supervision because withdrawal from alcohol can produce life-threatening seizures. Recall from Chapter 4 that alcohol boosts the inhibition produced by GABA, leading to alcohol’s classification as a central nervous system depressant. Because withdrawal symptoms are usually the opposite of drug effects, withdrawing from a depressant produces excitation, and too much excitation leads to seizures.
One of the remaining controversies in the treatment of alcohol dependence is whether a person can safely return to moderate drinking. Most psychologists do not believe that it is possible for recovered problem drinkers to resume alcohol consumption without relapse. In one 60-year longitudinal study of men with problem drinking, few returned to moderate drinking without experiencing a relapse (Vaillant, 2003).
Exercise
Exercise was not an option for our hunter–gatherer ancestors, for whom physical work meant the difference between death and survival. In today’s sedentary lifestyle, however, in which many workers spend hours commuting in cars to sit for more hours in front of computers, exercise becomes something that we must consciously remember to do. Children in previous generations would dash from school to play outdoors, but social changes, including lack of supervision at home and safety concerns, have led to much less spontaneous outdoor activity. Parents might prefer that their children stay indoors playing video games rather than ride their bicycles in the neighborhood. For many middle-aged and older adults, loneliness might lead to less physical activity (Hawkley & Cacioppo, 2010; Hawkley, Thisted, & Cacioppo, 2009).
Lack of exercise and sitting are related but different issues. Children and adults in the United States spend an average of 55% of their day sitting while riding in cars, watching television, doing work or attending school, and playing video games or doing other computer work (Matthews et al., 2008). A person’s amount of sitting time is correlated with risk of death (see Figure 16.18). However, high levels of moderately intense activity (60–75 minutes per day) seems to offset some of this risk (Ekelund et al., 2016). Although the highest risk of death occurs in obese individuals who spend nearly all their time sitting, the amount of time spent sitting also predicts mortality within a group of active individuals (Katzmarzyk, Church, Craig, & Bouchard, 2009).
Exercise not only benefits our bodies by keeping our muscles and cardiovascular systems in good shape, but also benefits our psychological well-being. A brisk 30-minute walk has emerged as an effective way to treat MDD, as discussed in Chapter 15 (Blumenthal et al., 1999). In addition to improving mood, exercise increases cognitive performance (Hogan, Mata, & Carstensen, 2013). One mechanism for this improvement could be the increased delivery of oxygen to the brain resulting from a fit cardiovascular system. Other research suggests that exercise also has the capacity to boost neurogenesis, particularly in the hippocampus of the brain (Gibbons et al., 2014). As you learned in Chapter 4, the hippocampus plays important roles in learning and memory.
We mentioned in an earlier section that stress can be detrimental to the functioning of the immune system. Exercise can be stressful as well; so what effect could it have? Not too surprisingly, we find complex relationships between the amount and type of exercise that a person performs and the response of the immune system. Compared to sedentary people, those who engage in regular moderate exercise enjoy a lower rate of infection (Gleeson, 2007). However, too much of a good thing, in the form of continuous, prolonged, and high-intensity exercise such as preparation for and competition in marathons and triathlons, can produce a temporary decrease in immune system function for about a day. Elite athletes, because of their constant and intense training schedules, often experience more minor illnesses, such as sniffles and colds, but the long-term benefits of exercise far outweigh these small vulnerabilities.
Loneliness and Health
Loneliness, or a perceived deficit in social connectivity, has long been understood as a risk factor for psychological disorders, but now it is understood to contribute to mortality in older adults as well (Cacioppo & Cacioppo, 2017). Even when other factors are controlled, loneliness produces a 26% increase in the odds of early death. Given the growing number of older adults and high prevalence of loneliness among them (20%–60% report being lonely some of the time, and 5%–10% feel lonely frequently or always), this presents a significant risk to health and well-being.
Loneliness produces risk for death along a number of pathways that are familiar to you by now: poor sleep quality, increased activity in the HPA axis, increased sympathetic activity relative to parasympathetic activity, altered gene expression in immune system cells, decreased immunity to viruses, increased inflammation, decreased impulse control, and increased symptoms of depression (Cacioppo & Cacioppo, 2017). While the amount of harm from changes in each of these pathways might be small, the combined and cumulative changes due to loneliness can produce significant damage to health and well-being (see Figure 16.19).